JP4219911B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve for an internal combustion engine.

  Conventionally, various fuel injection valves have been proposed. Patent Document 1 discloses a fuel injection valve as an example.

The fuel injection valve of Patent Document 1 generates a valve seat member in which a valve seat is formed, a valve body that is attached to and detached from the valve seat, an urging means that urges the valve body in a valve closing direction, and a magnetic attraction force. An electromagnetic coil for separating the valve seat, and fuel is injected when the electromagnetic coil is energized to separate the valve body from the valve seat, while when the electromagnetic coil is de-energized, The valve body is seated on the valve seat by the biasing means, and the fuel injection is stopped. Usually, in this type of fuel injection valve, both the valve seat member and the valve body are made of a metal material.
JP-A-10-122085

  However, in this type of fuel injection valve, in order to ensure the sealing performance in the seated state (valve closed state), a polishing process is performed to increase the surface accuracy of the valve seat member or the valve body. In order to suppress partial wear of the valve seat member or the valve body due to repetitive operation, a hardening process is performed, and there is a problem that it takes time and effort for processing.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a fuel injection valve with less processing effort.

In order to achieve the above object, according to a first aspect of the present invention, in the fuel injection valve, the valve seat member is made of a resin material, and the valve seat member is provided with a bottom wall portion substantially orthogonal to the valve closing direction. The bottom inner surface of the bottom wall portion and the bottom surface of the valve body are brought into surface contact with each other, and the gap between the bottom inner surface of the valve seat member and the bottom surface of the valve body is closer to the axial center side of the valve body. The purpose is to make it larger .

According to a second aspect of the present invention, in the first aspect of the present invention, an annular protrusion is formed on at least one of the upper surface of the valve seat member and the bottom surface of the valve body, and the protrusion is formed on the other surface. The seal is ensured by the contact area .

According to a third aspect of the present invention, in the first or second aspect of the present invention, a through-hole penetrating the front and back of the valve seat member is provided in a region downstream of a seal region between the valve seat member and the valve body. The air is introduced from the outside into the area inside the valve seat member due to the pressure drop caused by the fuel flow in the downstream area.
Furthermore, the invention of claim 4 is the invention according to any one of claims 1 to 3, wherein an injection hole is formed in the valve seat member .

According to invention of Claim 1, since the valve seat member was comprised with the resin material with high moldability compared with a metal material, compared with the case where a valve seat member is comprised with a metal material, the effort of a process can be reduced. it can. In addition, in a state where the valve body is separated from the valve seat, it is possible to ensure a gap more reliably between the upper surface and the bottom inner surface, and to relatively easily form a flow toward the injection hole. Furthermore, an annular region where the peripheral portions of the bottom surface of the valve body and the upper surface of the valve seat member are in surface contact can be used as a seal region, and sealing by seating can be realized with a relatively simple configuration. In addition, the area isolated from the pressurizing area is relatively large inside the seal area, and the shape of the isolated area and the degree of freedom of the layout of the injection holes can be increased. There is also an advantage that characteristics can be easily obtained.

According to the second aspect of the present invention, the projection can secure the sealing region more easily and more reliably, and the projection is provided, so that the bottom surface of the valve body and the top surface of the valve seat member are opened. Since the disturbance of the fuel flow in the gap of the fuel becomes large, there is an advantage that the atomization performance of the fuel spray is improved. In addition, the area isolated from the pressurizing area is relatively large inside the seal area, and the shape of the isolated area and the degree of freedom of the layout of the injection holes can be increased. There is also an advantage that it becomes easy to obtain.

According to the third aspect of the invention, the air flow introduced from the through hole formed in the valve seat member causes the fuel flow in the gap and thus the fuel flow in the injection hole to become more turbulent, and is introduced into the fuel. The air is agitated and fuel atomization can be further promoted.
Further, according to the invention of claim 4, the number of parts is reduced as compared with the case where the nozzle plate in which the injection holes are formed and the valve seat member in which the valve seat is formed separately as in the prior art. Manufacturing effort can be reduced and manufacturing costs can be reduced .

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments embodying the invention will be described with reference to the drawings. In the following, a fuel injection valve used for an internal combustion engine will be exemplified.

  (First Embodiment) FIG. 1 is a cross-sectional view of a fuel injection valve according to this embodiment (a cross-sectional view along the axial direction), and FIG. 2 is an enlarged cross-sectional view of the tip of the fuel injection valve. FIG. 3 is a cross-sectional view showing an enlarged front end portion of the fuel injection valve, and shows a seated state (valve closed state).

  The fuel injection valve 1 according to the present embodiment is connected to a boss portion (both not shown) provided in a fuel pipe, and injects fuel flowing through the fuel pipe into an internal combustion engine (intake port, cylinder, etc.). To do.

  The fuel injection valve 1 includes a casing 2, a cylinder 3, a core cylinder 5, a yoke 13, a resin cover 16 and the like as a main body.

  Among these, the cylindrical body 3 is formed as a thin metal tube having a step by, for example, subjecting a material such as a magnetic stainless material to press working such as deep drawing. In the present embodiment, a large-diameter portion 3a is formed on one end side in the axial direction of the cylindrical body 3, and a small-diameter small-diameter portion 3b is formed on the other end side. The end portion of the large-diameter portion 3a is The cylinder 3 is connected to the fuel pipe while being inserted into the boss portion of the fuel pipe.

  On the outer peripheral surface of the cylindrical body 3 (large diameter portion 3a) on the inlet side, an O-ring 18 that ensures liquid tightness between the cylindrical body 3 and the boss portion of the fuel pipe is provided.

  In addition, a filter 21 is attached to the opening on the inlet side (upstream side) of the cylindrical body 3. The filter 21 is integrally formed with the cored bar 21a using a cylindrical cored bar 21a that is press-fitted into the large-diameter portion 3a of the cylindrical body 3, and a resin material that is softer than the cylindrical body 3, such as nylon or fluororesin. The frame 21b is formed (injection-molded) and a mesh 21c that is attached to the frame 21b and allows fuel to pass therethrough.

  The core cylinder 5 is fitted inside the cylinder 3. The core cylinder 5 forms a closed magnetic path by the electromagnetic coil 15 together with the outer cylinder portion 8 of the valve body 6 and the yoke 13 and defines the valve opening position of the valve body 6. The core cylinder 5 is attached by being press-fitted into the small diameter part 3b of the cylinder 3, for example.

  A cylindrical valve seat member 9 is disposed at the downstream end of the cylindrical body 3. The valve seat member 9 includes a peripheral wall portion 9b formed in a substantially cylindrical shape, and a disk-shaped bottom wall portion that is substantially orthogonal to the axial direction (the opening / closing valve direction of the valve body 6) at the downstream end of the peripheral wall portion 9b. 9d. The valve portion 7 of the valve body 6 is accommodated in a recess 9c surrounded by the peripheral wall portion 9b and the bottom wall portion 9d.

  A plurality of injection holes 9f are formed in the bottom wall portion 9d as through holes that penetrate the front and back surfaces (inside and outside). The injection direction of the injection hole 9f is slightly inclined radially outward with respect to the axial direction. The bottom inner surface 9e of the bottom wall portion 9d is formed as a surface that is substantially orthogonal to the axial direction, but is formed in a convex shape that is inclined so that the axial center side slightly protrudes. In addition, although mentioned later in detail, in this embodiment, the peripheral part of this bottom inner surface 9e becomes a valve seat.

  In this embodiment, the valve seat member 9 is made of a resin material (so-called “PI” (polyimide), PEEK (polyethyl ether ketone), POM (acetal; polyoxymethylene)) having high chemical resistance and wear resistance (so-called “polyoxymethylene”). Engineering plastic). Since the resin material is excellent in moldability, it has the advantage that it is easy to ensure surface accuracy and can easily form a shape that generates a suitable fuel flow, as compared with the case where a metal material is used as in the past. is there. In the present embodiment, the distal end portion 3c of the cylindrical body 3 is bent inward, and the distal end portion 3c is bitten into the annular recess 9a formed on the outer peripheral surface of the valve seat member 9, but this configuration is integrated. Can be obtained by insert molding.

  Between the core cylinder 5 and the valve seat member 9, a valve body 6 that is axially displaceable within the small diameter portion 3b of the cylinder 3 is accommodated. In the present embodiment, the valve body 6 is formed of a magnetic metal material and is formed of a cylindrical shape that extends in the axial direction, and is formed of a resin material. And a spherical valve portion 7 that is separated from and seated on the bottom inner surface 9e of the seat member 9. In this embodiment, the uneven portion 8a formed on the inner wall of the outer cylinder portion 8 and the uneven portion 7d formed on the outer wall of the upper portion of the valve portion 7 are bitten together to be integrated. The configuration can be obtained by insert molding.

  The valve portion 7 includes an upstream bulging portion 7a bulging radially outward on the upstream side, a downstream bulging portion 7c bulging radially outward on the downstream side, and a bulging portion 7a having a narrower diameter. , 7c, and an intermediate portion 7b. The periphery of the intermediate portion 7 b is a fuel storage chamber 10.

  The upstream bulging portion 7a is formed in a bottomed cylindrical shape that opens to the end side, and the coil spring 12 is accommodated in the concave portion 6a. In addition, a through hole 6b that communicates the inside of the recess 6a and the fuel storage chamber 10 is formed in the bottom wall of the upstream bulging portion 7a. Further, a bottomed circular hole 7e penetrating from the intermediate portion 7b to the downstream side bulging portion 7c is formed in the center portion of the bottom wall, so that weight reduction and improvement in formability are achieved.

  A plurality of groove-like fuel passages 6c for supplying the fuel in the fuel storage chamber 10 to the injection holes 9f are formed at a predetermined pitch on the outer periphery of the downstream side bulging portion 7c. The fuel passage 6c may be formed so as to flow straight along the axial direction, or may be formed in a spiral to form a swirling flow. The bottom surface 6d is formed in a concave shape that is substantially orthogonal to the axial direction but is inclined so that the axial center side is slightly recessed. However, the inclination angle from the radially outer side to the inner side is made larger than the inclination angle of the bottom inner surface 9e of the valve seat member 9 facing the bottom surface 6d, and the clearance between the bottom surface 6d and the bottom inner surface 9e increases toward the axial center side. It is supposed to grow. In addition, it is preferable to form a bottomed hole 7f in the downstream bulging portion 7c as appropriate so as to reduce the weight and improve the moldability.

  Similarly to the valve seat member 9, the valve portion 7 is also made of a resin material (so-called “PI” (polyimide), PEEK (polyethyletherketone), POM (acetal; polyoxymethylene)) having high chemical resistance and high wear resistance. (Engineering plastic) is preferable.

  A coil spring 12 is provided as an urging means for applying an urging force in the valve closing direction to the valve body 6. The upper end of the coil spring 12 abuts on the lower end of a cylindrical adjuster 19 fitted in the core cylinder 5, while the lower end of the coil spring 12 is inserted into the recess 6 a of the valve body 6, An elastic force is generated in a direction extending in the axial direction. That is, the coil spring 12 is used as a compression spring, and exerts an urging force on the valve body 6 in a direction away from the core cylinder 5, that is, in a valve closing direction.

  A yoke 13 formed in a stepped cylindrical shape is provided on the outer peripheral side of the cylindrical body 3. In the present embodiment, the yoke 13 is press-fitted and fixed to the outer peripheral side of the small diameter portion 3 b of the cylindrical body 3. A connecting core 14 is provided between the yoke 13 and the small diameter portion 3 b of the cylindrical body 3. In the present embodiment, the connecting core 14 is formed as a substantially C-shaped magnetic body that surrounds the outer peripheral side of the small diameter portion 3b. A resin cap 11 that forms a groove of the O-ring 23 is attached to the tip side of the yoke 13.

  An electromagnetic coil 15 is provided between the cylinder 3 and the yoke 13. In this embodiment, the electromagnetic coil 15 includes a cylindrical coil bobbin 15a formed of a resin material and a coil 15b wound around the coil bobbin 15a, and the coil bobbin 15a is attached to the small diameter portion 3b of the cylindrical body 3. The exterior. The electromagnetic coil 15 is energized through the pins 20 of the connector 17 and the conductive wires 22 formed in the resin cover 16.

  The resin cover 16 is provided on the outer peripheral side of the cylindrical body 3. The resin cover 16 can be formed, for example, by injection molding in a state where the yoke 13, the connecting core 14, the electromagnetic coil 15, and the like are assembled on the outer peripheral side of the cylindrical body 3. The resin cover 16 and the connector 17 are integrally formed.

  In the fuel injection valve 1 having the above configuration, a biasing force in the valve closing direction is applied to the valve body 6 from a coil spring 12 as a biasing means, and the valve body 6 is not energized when the electromagnetic coil 15 is not energized. The seat is placed on the valve seat member 9, and the state in which the bottom surface 6d of the valve body 6 and the bottom inner surface 9e abut is maintained (valve closed state; FIG. 3).

  At this time, as described above, the bottom surface 6d of the valve body 6 has a concave shape that is inclined so that the axial center side is slightly recessed, while the bottom inner surface 9e of the valve seat member 9 is inclined so that the axial center side slightly protrudes. Since it has a convex shape and the gap between the bottom surface 6d and the bottom inner surface 9e increases toward the axial center side, the peripheral portions of the bottom surface 6d and the bottom inner surface 9e are in surface contact with each other when seated. Thus, the annular region S shown in FIG. 3 becomes a seal region. At this time, the seal region S is formed on the outer side in the radial direction from the injection hole 9 f formed in the bottom wall portion 9 d of the valve seat member 9.

  On the other hand, when the electromagnetic coil 15 is energized, a closed magnetic path is formed by the core cylinder 5, the outer cylinder portion 8, the yoke 13, and the like, so that the magnetic force in the direction close to the core cylinder 5 is applied to the outer cylinder portion 8. Works. Here, since this magnetic force (adsorptive force) is set to be larger than the urging force of the coil spring 12, when the electromagnetic coil 15 is energized, the valve body 6 is attracted to the core cylinder 5 and the valve body. 6 separates from the valve seat member 9, and the bottom surface 6d and the bottom inner surface 9e of the valve body 6 are separated (valve open state; FIG. 2).

  In this valve open state, the fuel flows down through the fuel passage 4 in the cylinder 3 and the core cylinder 5, and then passes through the adjuster 19 and the cylinder of the core cylinder 5, the recess 6 a above the valve element 6, and the through hole 6 b. Then, the fuel flows into the fuel storage chamber 10. Further, the fuel passes through the fuel passage 6 c formed on the outer periphery of the downstream side bulging portion 7 c from the fuel storage chamber 10, and the clearance between the bottom surface 6 d of the valve body 6 and the bottom inner surface 9 e of the valve seat member 9. Injected from the injection hole 9f.

  Here, according to the above configuration, in the present embodiment, the flow direction between the fuel flow Fa in the fuel passage 6c and the fuel flow Fb in the gap between the bottom surface 6d and the bottom inner surface 9e is substantially perpendicular or The direction of flow is substantially perpendicular or acute between the fuel flow Fb in the gap between the bottom surface 6d and the bottom inner surface 9e and the fuel flow Fc in the injection hole 9f. Will change greatly. The change in the flow direction causes separation or turbulent flow of the fuel from the wall surface. As a result, the flow of fuel ejected from the injection hole 9f is also disturbed, and stirring with the air proceeds, thereby atomizing the fuel spray. Is promoted.

  According to the above embodiment, since the valve seat member 9 is made of a resin material having a higher moldability than a metal material, the labor of processing is reduced compared to the case where the valve seat member is made of a metal material. Can do. In addition, it is easy to obtain a shape that produces a more suitable fuel flow by appropriately adjusting the shape according to the flow rate of fuel, the spray particle size, and the like. Further, there is an advantage that the sound pressure level of the seating sound can be lowered as compared with the case of using a metal material.

  Furthermore, according to this embodiment, since the part facing the valve seat member 9 of the valve body 6 and the contact part (valve part 7) are also made of the resin material, the shape of the part where the valve body and the valve seat member face each other. As a result, it is easy to obtain a shape that produces a more suitable fuel flow, and the sound pressure level of the seating sound can be further reduced.

  Furthermore, according to this embodiment, since the recessed part 9c was formed in the valve seat member 9, and the valve body 6 (valve part 7) was inserted in the said recessed part 9c, the inner surface of the mutually opposing recessed part 9c and The direction of the fuel flow toward the valve seat can be more easily adjusted by the shape between the valve portion 7 and the outer surface.

  Further, according to the present embodiment, the valve seat member 9 is provided with the bottom wall portion 9d substantially orthogonal to the axial direction (valve closing direction), and the bottom inner surface 9e of the bottom wall portion 9d and the bottom surface of the valve body 6 in the seated state. Since the surface is brought into contact with 6d, it is possible to form a flow toward the injection hole 9f relatively easily while ensuring a gap between the bottom inner surface 9e and the bottom surface 6d in a separated state.

  Further, since the injection direction by the injection hole 9f is set substantially perpendicular or acute to the bottom inner surface 9e or the bottom surface 6d, the fuel flow Fb between the bottom inner surface 9e and the bottom surface 6d and the fuel in the injection hole 9f Since the flow direction can be changed substantially perpendicularly or acutely with respect to the flow Fc, the flow ejected from the injection hole 9f induces separation or turbulent flow from the wall surface of the flow, and the air and the agitation. Can be promoted, and thus atomization of the fuel spray can be promoted.

  Furthermore, according to the present embodiment, the flow of fuel between the outer periphery of the valve portion 7 and the inner periphery of the recess 9c is configured such that the valve body 6 (valve portion 7) is inserted into the recess 9c of the valve seat member 9. The direction of flow can be changed substantially at a substantially right angle or acute angle between Fa and the fuel flow Fb between the bottom inner surface 9e and the bottom surface 6d. By inducing turbulent flow, the flow ejected from the injection hole 9f can be promoted to be agitated with air, and thus atomization of the fuel spray can be promoted.

  In addition, according to the present embodiment, the bottom surface 6d of the valve body 6 has a concave shape that is inclined so that the axial center side is slightly recessed, while the bottom inner surface 9e of the valve seat member 9 is inclined so that the axial center side slightly protrudes. Furthermore, since the gap between the bottom surface 6d and the bottom inner surface 9e increases toward the axial center side, the annular region S in which the peripheral portions of the bottom surface 6d and the bottom inner surface 9e are in surface contact with each other is sealed. The seal can be realized by a relatively simple configuration. In addition, a region that is isolated from the pressurizing region is relatively large inside the seal region S, so that the degree of freedom in layout of the injection holes 9f facing the isolated region can be increased, and more suitable injection. There is also an advantage that characteristics can be easily obtained.

  In addition, according to the present embodiment, the cylindrical body 3 that accommodates the valve body 6 is provided, and the valve seat member 9 is integrally molded with the cylindrical body 3 by resin molding. Can be easily obtained.

  Moreover, according to this embodiment, since the bottom inner surface 9e as a valve seat was formed in the valve seat member 9 and the injection hole 9f was provided, the nozzle plate and the valve seat in which the injection hole was formed like the conventional structure. Compared to the case where the formed valve seat member is configured as a separate body, the number of parts can be reduced, manufacturing effort can be reduced, and manufacturing cost can be reduced.

  (Second Embodiment) FIG. 4 is an enlarged sectional view showing the tip of a fuel injection valve according to this embodiment, showing a separated state (valve open state), and FIG. 5 is a fuel injection. It is sectional drawing which expands and shows the front-end | tip part of a valve, Comprising: It is a figure which shows a seating state (valve closing state). In addition, the fuel injection valve concerning this embodiment is equipped with the structure similar to the fuel injection valve concerning the said embodiment. Therefore, about the same structure, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In this embodiment, an annular projection 9g is formed on the bottom inner surface 9e of the valve seat member 9A, and a seal is secured by this projection. The annular projection 9g is provided to face the peripheral portion of the bottom surface 6d of the valve body 6A (valve portion 7A). When seated, the annular projection 9g and the peripheral portion of the bottom surface 6d are in surface contact with each other. The region S becomes a seal region.

  According to the present embodiment, there is an advantage that the seal area S can be more reliably secured by the protrusion 9g and the surface pressure of the seal area S can be easily set appropriately. In addition, since the protrusion 9g is provided, the fuel flow Fb in the gap between the bottom surface 6d of the valve body 6A and the bottom inner surface 9e of the valve seat member 9A at the time of valve opening increases, so the atomization of fuel spray is further reduced. There is an advantage of being promoted.

  (Third Embodiment) FIG. 6 is an enlarged cross-sectional view showing a tip portion of a fuel injection valve according to this embodiment, and shows a separated state (valve open state). In addition, the fuel injection valve concerning this embodiment is equipped with the structure similar to the fuel injection valve concerning the said embodiment. Therefore, about the same structure, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In the present embodiment, a through hole 9h that penetrates the front and back (inside and outside) is provided in the downstream (axial center side) region from the seal region (protrusion 9g) of the valve seat member 9B, and the valve body 6B (valve portion 7B). The fuel flow from the outside through the through hole 9h due to the pressure drop caused by the fuel flow Fb in the position where the opening of the through hole 9h faces in the gap between the bottom surface 6d of the valve seat member 9B and the bottom inner surface 9e of the valve seat member 9B Air is introduced into Fb. Due to the air flow A generated by such a configuration, the fuel flow Fb in the gap and thus the fuel flow Fc in the injection hole 9f become a more turbulent flow, and the agitation of the fuel and air is further promoted to further atomize the fuel. It can be further promoted. In addition, since the through hole 9h opens to the downstream side of the seal region, fuel does not leak through the through hole 9h in the valve-closed state.

  (Fourth Embodiment) FIG. 7 is an enlarged sectional view showing the tip of the fuel injection valve according to the present embodiment, and shows a separated state (valve open state). In addition, the fuel injection valve concerning this embodiment is equipped with the structure similar to the fuel injection valve concerning the said embodiment. Therefore, about the same structure, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In the present embodiment, the peripheral wall portion of the valve seat member 9 </ b> C is eliminated, and the valve body 6 </ b> C is guided by the inner periphery of the cylindrical body 3. Further, in the present embodiment, the valve body 6C is configured as a conductive resin material that is made conductive by binding a conductive filler to the resin material, and the outer cylinder portion 8 made of a metal material is formed from the valve body 6C. Omitted. A recess 6a that accommodates the coil spring 12 is formed in the valve body 6C (valve portion 7C), and a through hole that communicates the fuel storage chamber 10a in the recess 6a with the fuel storage chamber 10b outside the intermediate portion 7b. 6e is formed, and the fuel is between the fuel storage chamber 10a, the through hole 6e, the fuel storage chamber 10b, the outer periphery of the downstream bulging portion 7c, and the bottom surface 6d of the valve body 6C and the bottom inner surface 9e of the valve seat member 9C. It is made to inject from the injection hole 9f via the gap | interval. According to this configuration, the amount of resin material used in the valve seat member 9C can be reduced, and the number of parts of the valve body 6C can be reduced and the size can be further reduced. Can help. Further, as compared with the above embodiment, there is an advantage that the pressure fluctuation (surge pressure) of the fuel can be reduced as much as the volume of the region where the fuel exists can be reduced.

  The present invention can be embodied in another embodiment as follows. In other embodiments described below, the same operations and effects as in the above embodiments can be obtained.

  (1) The protrusion that forms the seal region between the valve body and the valve seat member may be provided on at least one of the valve body and the valve seat member, but may be provided on both.

  (2) The protrusions and grooves that determine the fuel flow direction may be provided on at least one of the valve seat member and the valve body, but may be provided on both. Moreover, you may provide a processus | protrusion and a groove | channel in the part inside the seal | sticker area | region of the bottom inner surface of a valve seat member, and the seal | sticker area | region of the bottom face of a valve body.

  (3) The present invention can be realized with specifications according to the fuel pressure.

  Further, technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.

  (A) In the fuel injection valve according to the first to third aspects, it is preferable that the portion where the valve seat member faces or contacts the valve body is made of a resin material.

  In this way, the shape of the portion facing or abutting the valve body can be appropriately adjusted to make it easier to obtain a shape that produces a more suitable fuel flow, and the sound pressure level of the seating sound can be further lowered. .

  (B) In the fuel injection valve according to claims 1 to 3 or (a), it is preferable that a recess is formed in the valve seat member and the valve element is inserted into the recess.

  In this way, the direction of the fuel flowing toward the valve seat can be more easily adjusted by the shape between the inner surface of the concave portion and the outer surface of the valve body facing each other. In addition, according to this configuration, the flow direction between the fuel flow between the outer periphery of the valve element inserted into the recess and the inner periphery of the recess and the fuel flow between the top surface and the bottom surface. Can be changed substantially at a right angle or at an acute angle, which induces flow separation and turbulence to promote the stirring of the flow ejected from the injection holes with the air, and thus atomization of the fuel spray. Can be promoted.

  (C) In the fuel injection valve according to claims 1 to 3 or (a) and (b), the axial direction of the injection hole is substantially perpendicular to the bottom inner surface of the valve seat member or the bottom surface of the valve body, or It is preferable to set an acute angle.

  In this way, the flow direction can be changed substantially perpendicularly or acutely between the fuel flow between the bottom inner surface and the bottom surface and the fuel flow in the injection hole. Separation and turbulence are induced, and the flow ejected from the injection hole is promoted to be agitated with air, and as a result, atomization of the fuel spray can be promoted.

Sectional drawing of the fuel injection valve concerning embodiment of this invention (figure of the cross section along an axial direction). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 1st Embodiment of this invention was expanded, Comprising: The figure which shows a separated state (valve-opening state). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 1st Embodiment of this invention was expanded, Comprising: The figure which shows a seating state (valve closed state). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 2nd Embodiment of this invention was expanded, Comprising: The figure which shows a separated state (valve-opening state). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 2nd Embodiment of this invention was expanded, Comprising: The figure which shows a seating state (valve closing state). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 3rd Embodiment of this invention was expanded, Comprising: The figure which shows a separated state (valve-opening state). It is sectional drawing to which the front-end | tip part of the fuel injection valve concerning 4th Embodiment of this invention was expanded, Comprising: The figure which shows a separated state (valve-opening state).

Explanation of symbols

1, 1A, 1B, 1C Fuel injection valve 3 Tubular body 6, 6A, 6B, 6C Valve body 6d Bottom surface 9, 9A, 9B, 9C Valve seat member 9d Bottom wall 9e Top surface (valve seat)
12 Coil spring (biasing means)
15 Electromagnetic coil

Claims (4)

A valve seat member formed with a valve seat;
A valve body that is separated from and seated on the valve seat;
Urging means for urging the valve body in the valve closing direction;
An electromagnetic coil for generating a magnetic attractive force to separate the valve body;
In a fuel injection valve equipped with
The valve seat member is made of a resin material ,
The valve seat member is provided with a bottom wall portion substantially orthogonal to the valve closing direction, the bottom inner surface of the bottom wall portion and the bottom surface of the valve body are in surface contact in a seated state, and
A fuel injection valve characterized in that a gap between a bottom inner surface of the valve seat member and a bottom surface of the valve body becomes larger toward an axial center side of the valve body . An annular protrusion is formed on at least one of the upper surface of the valve seat member and the bottom surface of the valve body, and a seal is secured by a region where the protrusion is in surface contact with the other. Item 4. The fuel injection valve according to Item 1. A through hole penetrating the front and back of the valve seat member is provided in a region downstream of the seal region between the valve seat member and the valve body, and the valve seat is caused by a pressure drop caused by a fuel flow in the downstream region. 3. The fuel injection valve according to claim 1, wherein air is introduced from outside into a region inside the member . The fuel injection valve according to claim 1, wherein an injection hole is formed in the valve seat member.

Images